payments.gno

 1package mint
 2
 3import (
 4	"chain"
 5	"chain/banker"
 6	"chain/runtime/unsafe"
 7)
 8
 9// I-3: this realm holds no balance. Each paying function receives the
10// attached ugnot and pushes every unit out before returning: protocol fee,
11// creator payees, and the refund. Nothing is ever kept for later.
12
13// received returns the ugnot attached to a direct wallet call. Payments are
14// accepted only when a wallet called us: the origin-send envelope is shared
15// by every realm on the path, so a realm in between could have consumed it
16// (chain/runtime/unsafe.OriginSend).
17func received(cur realm) int64 {
18	if !cur.Previous().IsUserCall() {
19		panic("payments must come directly from a wallet, not through another realm")
20	}
21	sent := unsafe.OriginSend()
22	for _, c := range sent {
23		if c.Denom != "ugnot" && c.Amount != 0 {
24			panic("only ugnot is accepted")
25		}
26	}
27	return sent.AmountOf("ugnot")
28}
29
30// assertNoDeposit refuses coins on functions that take none (RA L-1).
31func assertNoDeposit(cur realm) {
32	if cur.Previous().IsUserCall() && !unsafe.OriginSend().IsZero() {
33		panic("this function does not accept coins")
34	}
35}
36
37func pay(cur realm, to address, amount int64) {
38	if amount <= 0 {
39		return
40	}
41	banker.NewBanker(banker.BankerTypeRealmSend, cur).
42		SendCoins(cur.Address(), to, chain.NewCoins(chain.NewCoin("ugnot", amount)))
43}